Patent US4560030A successfully refreshed from Google Patents.
US4560030A
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US
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Folding ladder
Assignee: METARPLASTIC SpA VIA DELLE INDUSTRIE 37 30024 MUSILE DI PIAVE (VENICE ITALY)
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Filing: 1984-07-25
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Granted: 1985-12-24
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Expires: 2004-07-25
Abstract
Abstract A folding ladder comprising two pairs of uprights hinged at their top and a plurality of rungs connected to said uprights, in which each rung is formed from two equal portions hinged together and is connected to the other rungs at said point of mutual hinging by a rod parallel to the uprights. Moreover the rungs are hinged at their ends to said uprights for passing from the working configuration of the ladder in which they are orthogonal to the uprights, to the folded configuration of the ladder in which they are substantially parallel to the uprights.
Inventors
- 👤 Aldo Mucelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:32
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/02; E06C1/38; E06C1/39; E06C1/393; E06C1/383; E06C1/3835
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A folding ladder comprising two pairs of uprights (1,1', 2,2') hinged at their top and a plurality of rungs (4) connected to said uprights, characterised in that each rung (4) is formed from two equal portions (4') hinged together and is connected to the other rungs (4) at said point of mutual hinging by a rod (8,8') parallel to the uprights, and in that the rungs (4) are hinged at their ends to said uprights for passing from the working configuration of the ladder in which they are orthogonal to the uprights, to the folded configuration of the ladder in which they are substantially parallel to the uprights, each pair of uprights being provided lowerly with a stop structure (9) constituted by two bars (10) hinged at their inner end to a block (11) in which the central rod (8,8') slides, and hinged at their outer end to the upright (1,1', 2,2'), said bars acting as struts on said block (11) when the ladder is in its working state.
Claim 2
Dependent Claim
169 words
A folding ladder comprising two pairs of uprights (1,1', 2,2') hinged at their top and a plurality of rungs (4) connected to said uprights, characterised in that each rung (4) is formed from two equal portions (4') hinged together and is connected to the other rungs (4) at said point of mutual hinging by a rod (8,8') parallel to the uprights, and in that the rungs (4) are hinged at their ends to said uprights for passing from the working configuration of the ladder in which they are orthogonal to the uprights, to the folded configuration of the ladder in which they are substantially parallel to the uprights, each pair of uprights being provided lowerly with a stop structure (9) constituted by two bars (10) hinged at their inner end to a block (11) in which the central rod (8,8') slides, and hinged at their outer end to the upright (1,1', 2,2'), said bars acting as struts on said block (11) when the ladder is in its working state.
Claim 3
Dependent Claim
135 words
A folding ladder comprising two pairs of uprights (1,1', 2,2') hinged at their top and a plurality of rungs (4) connected to said uprights, characterised in that each rung (4) is formed from two equal portions (4') hinged together and is connected to the other rungs (4) at said point of mutual hinging by a rod (8,8') parallel to the uprights, and in that the rungs (4) are hinged at their ends to said uprights for passing from the working configuration of the ladder in which they are orthogonal to the uprights, to the folded configuration of the ladder in which they are substantially parallel to the uprights, and a platform (14) constructed in three foldable portions, the central portion (14') being hinged to the upper rung of one of the two pairs of uprights.
Claim 4
Dependent Claim
135 words
A folding ladder comprising two pairs of uprights (1,1', 2,2') hinged at their top and a plurality of rungs (4) connected to said uprights, characterised in that each rung (4) is formed from two equal portions (4') hinged together and is connected to the other rungs (4) at said point of mutual hinging by a rod (8,8') parallel to the uprights, and in that the rungs (4) are hinged at their ends to said uprights for passing from the working configuration of the ladder in which they are orthogonal to the uprights, to the folded configuration of the ladder in which they are substantially parallel to the uprights, and a platform (14) constructed in three foldable portions, the central portion (14') being hinged to the upper rung of one of the two pairs of uprights.
Claim 5
Dependent Claim
58 words
A ladder as claimed in claim 2, characterised in that the central portion (14') of the platform (14) is connected to the upper rung of one of the two pairs of uprights by means of a small bar (13) provided with means for confining the corresponding uprights of the two pairs when in their position of mutual proximity.
Claim 6
Dependent Claim
59 words
A ladder as claimed in claim 3, characterised in that the small bar (13) is hinged to the upper end of one of the two rods (8,8') and is provided with a slot portion (16) for engaging the upper end of the other rod when the corresponding uprights of the two pairs are in their position of mutual proximity.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |